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C. H. QUINN. TENSIONING DEVICE FOR CAR DYNAMOS.

APPLICATION FILED MAY 23. I918.

Patented Oct. 14; 1919.

THE COLUMBIA PLANcmzAPH c0., WASHINGTON. n. c.

as: rare CHARLES H. QUINN", 0F ROANOKE, VIRGINIA,

TENSIONING- DEVICE FOR CAR-DYNAMOS.

Specification of Letters Patent.

Patented Oct. 14, 1919.

Application filed May 23, 1918. Serial No. 236,118.

To all whom it may concern Be it known that I, CHARLES H. QUINN, a citizen of the United States, residing at Ixoanoke, in the county of Roanoke and State of Virginia, have invented certain new and useful Improvements in Tensioni'ng Devices for Car-Dynamos; and I do here-by dcclare the following to be a full, clear, and exact description of the invention, such as will enable others skilled in the art to which it appertains to make and use the same.

The invention relates to car axle-driven dynamos and more particularly to means for automatically tensioning the driving belt which connects the pivotally supported generator to the car axle.

The principal object of my invention, generally stated, is to provide a belt tensioning device carried by the car framing and acting through differential means to maintain a constant tension On the belt in all positions of the dynamo.

Another object of my invention is to provide a belt tensioning device which avoids the use of springs as the means for maintaining the belts in driving relationship and substitutes therefor a gravity acting means for maintaining at all times a constant tension upon the dynamo belt.

There are many other features of the invention which will be pointed out in connection with the detailed description of the specific embodiment thereof which have been illustrated in the accompanying drawings, in which Figure 1 is a view in side elevation. of a portion of a car underframe, showing the application of the invention thereto,

Fig. 2 is a fragmentary view in elevation of an axle-driven dynamo and the supporting cradle,

Fig. 3 is a transverse vertical sectional .vicw taken on the line 33 of Fig. 1, look ing toward the dynamo, and

Flg. 4 1s a fragmentary vlew in elevation of a slightlv modified construction.

Throughout the specification and draw-- otally supported on the suspension bars 3 is the dynamo supporting frame or cradle 4. The manner of pivotally supporting the cradle t from the bars 3 is fully described and claimed in my copending application Serial No. 188,141, filed October 29, 1917, and hence need not be described in detail.

It will be sufiicient to state that each bar '3 is provided with a saddle 5 and that the cradle 4 as shown at 12. To the outwardly extending end of the bracket 11 is pivotally connected a jaw member 13 by means of the pin 11, the said jaw member 13 being connected in any suitable manner to the end of a flexible member 15, which may and preferably is formed as a wire rope or cable.

At a point in rear of the normal position of the cradle, the car underframe is provided with a plurality of alined openings 16 which are adapted to form the journal bearings for a shaft 17 These openings may, for convenience, be formed in the center sills 1, 1 as shown. Intermediate the said sills the shaft 17 is provided with an eccentric pulley 18, which is preferably adjustably connected to the said shaft by any of the ordinary ways commonly employed in this type of construction. A pair of sleeves 19 may be provided, each of said sleeves being adapted to be loosely received on the said shaft 17 between one of the said sills and the adjacent hub 20 of the pulley 18.

One end of the shaft 17 is adapted to eX- tend through one of the openings 16 so as to project a short distance beyond the outer face of the adjacent sill and on the projecting end 21 of the shaft is mounted an eccentric pulley 22. This pulley is also adjustably fixed to the shaft 17 in any suitable or convenient manner.

To the depending portions of the center sills 1 is connected a weight guide 23 which may and preferably does comprise a U- shaped strap having the upwardly extending arms 24.- thereof positioned in alinement with the plane of the pulley 18. The weight guide 23 is preferably maintained in position by means of the V-shapedbrackets 25 and 26 and the angle bars 27 and 28.

Connected to the pulley 18 in any convenient manner is a flexible member or cable 29 which is adapted to lie within the groove 30 of the pulley and extend downwardly there-from between the arms 2% of the weight guide To the free end of the cable 29 is connected the weight 31 the end faces of which are recessed as at 32 to reoeive the arms 24 of the Weight guide.

The inner end of the cable 15 is connected to the pulley 22 within the groove 34 thereof in any convenient manner,

The pulley 9 of the generator or dynamo 10 is operatively connected to the car axle pulley 9 by means of the belt 33. In the drawings the parts 9 and 33 are indicated by dotted lines.

The eccentric pulleys 18 and 22 are conneoted'to the shaft so that when the generator cradle l lies in a vertical plane the weight arm of the pulley 22 will equal in length the power arm of the pulley 18 and the eccentricities of the pulleys are such that when the cradle swings toward the truck the weight arm of the pulley 18 decreases but when the cradle swings in the opposite direction from the vertical the weight arm of the pulley18 increases.

The differential action above described maintains at all times a constant tension upon the belt 33. For when the cradle swings toward the truck frame the weight of the generator acts to swing the generator back to the vertical and hence tends to tighten the belt 33 and hence less power is required by the tensioning device, but when the generator swings away from the truck the tendency to return to the vertical results in loosening the belt 33 unless more tension is applied by the tensioning device.

The result may be obtained by employing the construction shown in Fig. & wherein levers 18 and 22 are shown as replacing the eccentric pulleys disclosed in the other views. The said levers 18 and 22 forming a belt crank arrangement wherein the power and weight arms are increased or diminished automatically as required to maintain a constant belt tension.

As clearly shown in Fig. 1 the tension on r the belt 33 may be adjusted to any desired degree by means of the additional weights which are adapted to be positioned within the weight guide 23 and to be supported by the weight 31.

By the foregoing description of the device I do not intend to limit myself to the precise details shown and it is to be understood that the terms employed are to be understood in their descriptive and not in their limiting sense.

VVhatI claim is:

1. In a car underfrai'ne, the combination with a pivotally supported generator which is operatively connected to the car axle by means of a belt, of means adapted to main tain a constant tension upon the generator belt under all service conditions.

2. In a car underframe,-the combinationwith abelt driven pivotally supported elec tric generator, of differentially acting means for applying a substantially constant ten sion to said generator belt under all service conditions.

3. In a car underfraine, the combination with a belt driven pivotally supported electric generator, of differential means sup-- cable connected to the dynamo support and I I to a member attached to the underfraine.

In testimony whereof I afiix my signature.

CHARLES H. QUINN.

Copies of this patent may be obtained for five cents each, by addressing the Commissioner of Patents. Washington, D. G. 

